With the emergence of inhibitory processes late in the first year, infants begin to exhibit primitive voluntary regulation. Our investigation is a developmental cognitive neuroscience examination of the development of inhibitory control. Using a longitudinal design, we will test whether behavioral and neurophysiological levels of analysis reflect distinctions in two specific types of inhibitory control during infancy: attention inhibition and cognitive inhibition. Infants will be seen monthly from 5 to 12 months of age and complete inhibitory control tasks while brain electrophysiology is recorded. We will use behavior, EEG power, and EEG coherence to characterize the development of types of inhibitory control processes. Our proposed study is critical for understanding early cognitive development. There is a need in the scientific community for research that characterizes normal trajectories in early cognition in order to distinguish individual differences in development from non-optimal trajectories. Our study will provide that basic science foundational work on inhibitory control. We will address three research questions. 1) What is the distribution of performance on the inhibitory control tasks? 2) Is performance on the different types of inhibitory control tasks correlated at each age? 3) What are growth rates of the two types of inhibitory control from 5 to 12 months of age?